Battling Fruit Pests At The Wrong Time If you spray your fruit trees right after they bloom in the spring, it does more damage than good, hurting bees - not the pests. Researchers at the Corvallis Western Agricultural Research Center had advice for the public about insecticide spraying at the right time. The Montana State University specialists have studied worms that infest apples and pears and have found that codling moths are cold-blooded, so spraying when the blooms start is too early. Katrina Mendrey, orchard program manager at the Corvallis Ag Research Center, said in a news release, "When trees start to bloom, folks get excited about protecting their fruit. But spraying insecticides during bloom not only doesn't control the target pest, it harms bees and hence, reduces fruit pollination." She said to be patient and wait until temperatures rise. Then use controls such as wrapping and bagging fruit, along with the spraying.